PITTSBURGH -- While only the Steelers know his exact status, there are legitimate concerns as to whether Troy Polamalu will return anytime soon after aggravating a right calf injury Sunday.

This is the same calf that kept him out of practice leading up to last season's playoff game in Denver. Eight months later, Polamalu said he injured his right calf the week leading up to the season opener in Denver and aggravated in the game. A month after resting it, he didn't last one quarter Sunday. How long will it take for a third comeback? Can the 31-year-old return this season?

Polamalu couldn't put any weight on the leg as he limped off the field following a fumble by Michael Vick. Last week, when it looked like Polamalu was coming back, ESPN injury expert Stephania Bell said there was a risk of tearing the calf muscle more and making it a bigger injury, which could sideline him for multiple weeks.

"We don't know the extent of it," Steelers coach Mike Tomlin said about Polamalu's injury after the game.

The Steelers lose more than one of the game's top playmaking safeties. He's the quarterback of the defense. In the minutes that he played Sunday, you saw him pointing to get his teammates lined up correctly.

Polamalu's teammates took the setback hard.

"I almost had a mental collapse when I saw him get hurt," Steelers safety Ryan Clark said. "Sometimes I think my love for him is a negative. When he's not playing, I want him out there. It's no indictment on the guys who come in. But part of why I play here and part of why I come back every year is to play with him."

Clark added, "You hurt selfishly, but more for him. I know how bad he wants to be out there. I know how hard he worked to get back. I know what type of treatments he went through. I saw him in the cold tubs at 6:30 when I got to work and he was already done with his workouts. And to come back and for that to happen is just terrible."

It's unlikely that Polamalu and linebacker LaMarr Woodley will play Thursday night at Tennessee. Woodley injured his hamstring in the first half Sunday and didn't return.

"Working on a short week is probably not a good sign for him," Tomlin said of Woodley.